Juanita, On Tue, Sep 8, 2009 at 8:02 AM, juanita choo<juanitac...@gmail.com> wrote: > Hi, > > I have a data set consisting of the x and y coordinate locations of 1600 > points. I would like to generate a graph using the functions in igraph. > However the graph making functions in igraph requires the data to be in the > form of an adjacency matrix.
well, this is not quite true, there are quite a number of formats igraph can create graphs from, see graph.adjlist(), graph.formula(), graph.data.frame() or graph(). But you are right that graph.adjacency() is probably the easiest for you. > I'd like some advice on how to convert my point > pattern to an adjacency matrix or functions out there that would do it > directly. I've only gotten as far as obtaining the distance matrix using > dist(). You are almost there, then. You can filter your distance matrix if you like, and then create a weighted graph from the remaining edges: co <- cbind(rnorm(10), rnorm(10)) D <- as.matrix(dist(co)) D[ D > 2 ] <- 0 G <- graph.adjacency(D, mode="undirected", weighted=TRUE) Gabor > Thanks for the help. > > Best, > Juanita > > -- > Juanita Choo > Graduate Student > Section of Integrative Biology > University of Texas at Austin > 1 University Station Stop > TX 78712 > +1 512 471 5773 > > > > -- > Juanita Choo > Graduate Student > Section of Integrative Biology > University of Texas at Austin > 1 University Station Stop > TX 78712 > +1 512 471 5773 > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Gabor Csardi <gabor.csa...@unil.ch> UNIL DGM ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
